The extensive bleeding in the organs of 140,000 saigas in Kazakhstan has been explained to the Pasteurella and Clostridia bacteria, based on tissue samples obtained from the dead antelopes.
However, the unusually large number of dead antelopes - which even shocked conservationists who discovered entire heads of dead or dying saiga spread over open grasslands - has caused speculation on a reason beyond the natural, reports Express.
There are at least two theories that attempt to explain the death of the antelopes that halved the global population of the species.
UFO Sightsing Daily editor Scott Waring believes the mass antelope deaths are the result of an experiment by aliens. He claims the Kazakhstan government is aware that aliens use an underwater base in the country's Caspian Sea on the nation's borders.
Waring also cited the confirmation of that allegation by the head of the national Aerospace Agency of Azerbaijan, since the country used to be part of the Soviet Union which frequently tracked alien spacecraft that entered its waters. However, it was a secret due to security issues.
Another theory links the event to the Blood Moon or a sign of the Apocalypse or end times. The appearance of the Blood Moon on Sept. 28 has been connected to various events such as a speculated asteroid striking Earth which NASA debunked, Mirror reports.
For those who do not share Waring's explanation or believe it is already the end times, they can wait for scientists' explanation of the tragedy. The People's Trust for Endangered Species, a wildlife charity in Britain, launched a fund-raising appeal to help scientist study the cause of the death.